Carbureting system



y 1931. c. E. HOFBAUER CARBURETING SYSTEM Filed May 2, 1928 w w A a\ 2 Q 6" mgayroa ATTORNEY Patented May 19, 1931 CASPAR E. HOFBAUER, OF NEW YORK, N. Y.,

CORPORATION, OF NEW YORK, N. Y.,

r. orice A CORPORATION OF NEW YORK CARBURE'I'ING SYSTELI Application filed I'vIay Z, 1828. SerialNo. 274,421.

My invention relates generally to an arrangement whereby a fuel and air mixture is supplied to an internalcombustion engine, commonly referred to as a carburetor. My

invention has for an object thereof the provision of a fuel supply system arranged to prepare the fuel for most efiicient combustion for internal combustion engines and at the same time feed the fuel to-the point where it is prepared for best combustion from a distant point. The invention contemplates the provision of a carbureting system which will serve to efficiently prepare fuel for combustion at a point adjacent an internal combustion engine and feed the same to the mixing chamber from a source of supply located at a distance from the mixing chamber, such as is commonly known as the rear tank of an automobile, the admixture of the fuel, conditioning of the same.

with air and the feeding of the fuel to the point where air and fuel are admixed being accomplished by the induction resulting from variable pressures created by the reciprocating pistons within the cylinders of the internal combustion engine, preferably such as that induced by the diminished pressure head within the intake manifold of an internal combustion engine suchas is used in automobiles.

The invention contemplates the provision of a carbureting system including a primary air and fuel admixing portion serving as a fuel feeding and lifting device, characterized by an air Venturi flow and a secondary mixing chamber including an air port provided with a valve serving to apportion the quantity of air to be introduced into the secondary mixing chamber to take, care of a wide range of running conditions.

The invention contemplates the provision of a carburetor system of simple construction and design, which will efliciently and automatically lift fuel from a distance source and prepare it for efficient and economical consumptionin an internal combustion engine over a wide range of operating conditions, including idling speeds, as wellas running'conditions, such as may be encountered in pulling loads over steep grades, as well as level stretches of roadway. For the attainment of the foregoing objects and such further objects as may appear herein or be hereinafter pointed out, I make reference to theaccompanying drawings illustrating one form of my invention, in whichi Figure l is a cross sectional elevation through the main elements of my carbureting system, certain parts being omitted for the sake of clarity of illustration; j

Figure 2 is a fragmentary cross sectional plan view taken on the line 22 of Figural.

Referring to the drawings, and particularly to Figure 1, I have shown the main elements of my system comprising a primary lifting and mixing device (portion A, Figure l) and a secondary control and mix ing mechanism associated in relatively close proximity to and adjacent the engine (see portion E, Figure 1) sage between these portions of the system.

Referring now to the portion 'A, it will be observed that I have shown the fuel tank 11 having an air vent-1'2 and including'asupply of liquid fuel such as gasoline 13 therein.

Mounted within the tank, and extending downwardly into the fuel is a pipe or conduit 14 open at the bottom and terminating short of the lowermost portion of the tank. This pipe 14 may be suitably mounted in the tank by means of a flanged collar 15 or the like, to which the upper end of the pipele is attached. i

' Referring now, to the primary aspirating and mixing device A, one embodiment contemplates the provision of an air intake element 24 provided with a forwardly projecting nozzle 25, a portion of the outer walls of the latter being externally threaded to 'engage within the fitting 29,. It is contemplated that atmospheric air will enter into the element 24 and will be drawn through the nozzle 25. v

There is provided a separate fitting 29 having a bore therethrough which comprises two conical portions 30 and 31 converging towards the central portion to a more restricted junction 32 which however presents ASSIG N'O R TO PARAMOUNT OARBURETOR and a connecting pas tion up throughthe; pipe arrangement, to which a slightly smaller opening than the restricted discharge through the element 25. The fitting 29 is suitably interiorly threaded at its one end so that one end thereof may make engagement with the element 2% and is also threaded externally at its opposite end so that a; suitable union may be made between the latter and the main casting, as will be described hereinafter. It will be observed that-the borethrough the fittings24 and 29 gives a change of velocity to any material flowing therethrough, and for this purpose, in my preferred form, this bore is made-in the form of a Venturi tube. The venturi is made up in part of the nozzle 25 and of the bore 31. That conical which is disposed toward the more abrupt in angularity and shorter than the other portion 31 which communicates with'the-main casting. It will be observed that-the nozzle 25 isso constructed as to be spaced from bored portion 30. It will be further observed that an annular chamber 34- is thereby produced encirclingthe'endof the nozzle 25 and communicating with the space between the constricted portion 25 of the nozzle and the constricted portion 32 of the Venturi member 29. i

Before proceeding withthe more detailed description of the other'elements of the carbureting device, the operation of the primary lifting? means and of the primary, aspirating device- 7 will be elaborated.

suction and flow through the venturi'. This flow not only drawsair inwardly'through the opening 26' and intoand through the nozzle 25g but it'serves to draw fuel in liquid condi- 17 into the primary mixing chamber, to; which it is connected by the fitting: 17; to the nipple 16, in which is disposed-the jet 16". I

. The fue'l' passing through the pipe 17 is their drawn to the restricted opening or jet 16' and-into the chamber formed between the fittings 2%- and 29; This chamber, as will beobserved, is so formed as to cause the fuel to take the form of ahollow inclined annulus which is discharged into the venturi atthe point 32- which is the narrowest part of the Venturi, and there meets with and is'accelerated by theflow of a solid column of air through the. nozzle 25, As: a result of this sion primary liftingv and aspirating means. not only is a mixture of air and-gas formed of'a; substantially uniform character, but the fuel is caused condition and to be mixed with the airin a manner so asto form a stable primary mixture. The parts of my carburet-ing, system are so arranged and constructed that this primary mixture of air and gasis of a character too rich to be employed for ordinary engine portion of the Venturi' fitting 25 is and project into the conically' The invention {*1 contemplates the provis on ofa substantial I apply the expresto assume a finely comminuted operation, and I will now proceed to describe the manner in which this primary mixture is converted into a mixture which is uniform as to its ratio of gas to air, and which is fed to the engine at a rate in accordance with engine requirements under all running conditions.

Referring now more particularly to the left hand portion B, of Figure 1, it will be ob served that the forward endof the venturi fitting 31 is suitably associated withand connected to a main casting or member by being threaded into an internally threaded neck 61, integral with the casting 60.

The neck 61 is so arranged with respect to the casting 60 as todirect the primary mixture into an annular chamber similar. to,-but larger than the primary mixing. chamber 3 1, the mixture being preferably leadinto-the annular chamber in a direction tangential to the periphery. (See Figure 2). This chamber will be hereinafter referred to as the seconds ary mixing chamber, and constitutes apor tion of the secondary mixing or controlling device hereinbefore referred to, tending to perfect the mixture first formed.

The secondary mixing chamber is constituted by anupwardly disposed nozzle member 62 mounted within an inwardly directed annular flange integral with the castingGO and arranged slightly below the neck 61. The member 62 tapers upwardly and is of a lengthpreferablyto be in the direct path-of the fuel mixture coming inthrough the neck 61, and to have its edge 62' at substantially thev axial line of the cone 31, preferably just slightly below the same. Withinthe upper portion of: the casting. (SO-there is arranged atubular' fitting or bushing 63, whose lower edge 63' is at substantially the axial line of the cone 31 and preferably just slightly abovethe same, so as to leavea circumferential slot 64%, providing an openingrto the annular chamber 64:, formed by the conical walls 65 and 66' on the members 62 and 63, respectively. The widest dimension of the ch amber is about the same as the widest dimension of'the cone 31, and the intersecting throat or orificej66 is so disposed as to have the cone substantially tangentially disposed to the chamber, asbest shown in Figure 2. v f I i In the path of the cone 31 and afiixed to the member 62, there is disposed a substantially U sh'aped tubular member 36, radially disposed, with one arm 37 of thetube in the fitting 62 flush with the rearwa'll 65 and with the opening 37"at' the bottom of the annular space 641-". The opposite end 38 of the U- shaped tube extends upwardly to be at sub serves as a trap for a small amount of fuel for starting purposes, to be hereinafter de-v scribed, as well as augmenting the thoroughness of the final admixture of air, and fuel.

Above the bushing 63, the casting 60 is provided with a flange adapted for connection to theintake manifold of the engine in any of the number of well-known ways; and within theupper portion of the casting 60, the usual throttle valve 71 is provided.

Before describing in detail the automatic operation of the elements, it may be explained that it appears thatunder all conditions of operation additional air is drawn upwardly through the members 62 under controlled conditions by the suction produced within the intake manifold. This air attains a great velocity at the upper end of the member 62,

and it will be readily understood that the fuel mixture which has been caused to swirl around the secondary mixing chamberwill be picked up and directed upwardly through the fitting 63 along with this additional air entering through the member 62. Additional mixing and vaporizing will occur as the mixture passes through the annular chamber 64' and through the constriction 64 and by the tube 36 and across the opening 38.

The controlling device comprises a conical valve 67 normally resting by. gravity upon and closing an opening produced by an internal flange below the member 62. The flange 7 5 constitutes the upper wall of an air intake element 7 6 which is substantially cylindrical and is provided with openings 77 for the admission of air. The intake element 76 is considerably larger than the intake element 24, as are the openings 77 with respect to the opening 26, and it will be understood that the main portion of the air necessary for the formation of a proper mixture is supplied through the element 76.

The valve 67 is more or less controlled in its movement by the dash-pot arrangement shown as carried below the element 76. More particularly, I.-prefer to provide a chamber 80 adapted to contain liquid, and I have shown thevalve -67 provided with a downwardly projecting stem 81, the latter being slidably mounted within a bearing portion 82 depending from the lower wall 83 of the chamber 76. At its lower end, the stem 81 is provided with a piston 84 or the like, present ing an increased area to the liquid whereby the movement of thevalve 67 will be suitably retarded and dampened.

The dampening piston 84 has associated therewith a secondary piston 85in the form of a thin disc of large diameter and arranged to prevent a greater retarding surface and has a lost motion connection with the stem 81as follows .The secondary piston 85 is received in a reduced portion of the piston 84 so as to permit of a free limited movement of the secondary piston 85. Spacing movement of thevalve 67, the stem 81 and the piston 84 will move relatively to the piston 85 at the beginning of the movement.

The disc piston 85 as will be observed upon viewing Figure l of the drawing has its inner edge so dimensioned and arranged as to fit loosely on the piston 84 so as to provide a clearance between this edge and the adjacent wall of the piston. The outside edge of the piston 85 is however so arranged as to pro-- vide a rather close fit inside of the wall or skirt 116 of the chamber 80. Inside of the upper circular ridge 86, the piston 84 is provided with one or more openings 84, therethrough.

As a result of this arrangement, it will be understood that not only is the disc piston 85 self-aligning and always true as to its position in the chamber 80 but also upon the un seating of the disc piston 85 fro-m its position as shown in the drawings, which occurs on the downward movement of the piston 84, a free passage is provided through the opening or openings 84 and through the clearance around the inner edge ofthe piston 85 to beneath the piston 84. In this way, the downward movement of the piston is caused to be made more quickly than the upper movement under the same character of impulse.

. It is of course desirable that the starting mixture have an increased richness, and in order to control the continuation of this supply of relatively rich mixture, the valve 67 may be arranged and constructed to permit manual control thereof. For this purpose, I may employ a manually controllable lever 100, the outer end of which may be onerated by a lead 101 of which a spring 102 forms apart, from asuitable point on the dashboard so that it may be controlled. The

inner end of the lever is arranged to engage the upper end of the valve 67. In this manner, what amounts toan increased weight may be given the valve.

Once the engine has started, the suction will immediately operate to lift the valve 67 off of its seat. This lifting movement will be initially retarded by the piston 84 and the amount of openingproduced by the valve 67 will depend upon the speed of the engine. At any constant rate of speed, the valve 67 will flutter or float at'a predetermined point,

to permit the admission of a predetermined amount of air through the openings 77. It

will be understood that the valve; 67 will reinainoffits-seat in all conditions. of engine operation.

It will therefore be seen that a vacuum will be serving to provide a-primary or basic, somewhat vaporous mixture throughout the running'periodof the engine. The parts are so proportioned and arranged that this initial mixture is richer than thatrequired fornormalautomobile engine operation, and it will be observed that the secondary mixing chamber accomplishes the function, among other things, of reducingthe: richness of the mixture. Y

It will befurther observed that the final richness is controlled by tl e amount of air supplied through the openings-'1"!- instead of bya needle valve of the usual'type which controls the-amount of gasoline. Inasmuch as a suitable mixture comprises proportions of air and fuel in the neighborhood of 1% to 1, it will be obvious that the control of the'14 factor instead of thel factor will renderinaccuracies of design and maladjustment of parts less effective in causing defec tive operation. I consider this an import-ant feature of my invention.

Another feature which I consider of great importance is the arrangement whereby fuel in sprayed or vaporized condition is picked npfroin an annular chamber by air passing through said chamber in an axial direction. This featurewill be clearly observed in connection with both the primary and secondary mixing chambers, and itwill be obvious to those skilled in the art that an arrangement of this character is fundamentally different from that employed in connection with the ordinary carburetor in that conditions are attained wherein the flow induced by the intake manifold is more accurately proportioned between air and fuel; or air and fuel mixture because each agent is conditioned or prepared to be more readily responsive in supply.

A particular feature of the present invention resides in utilizing gasoline as theretarding liquid within the chamber 80. For

utilizing gasoline as the retarding fluid lies in the fact that this fluid may be utilized in mod ifying the richness of the mixture at certain critical periods of the running of the. engine.

Thus, in the embodiment shown, I have shown the valve 67 and its ste1n8las provided with a lon 'itudmal boreor passageway 94 opening through the valve 67 at its upper end. The passageway 94 communicates at its lower end throughthe transverse connecting channel 95 with the interior of the chamber 96' formed between the" fixed lower end of the depending bearing 82'andthe interior of the chamber 97 formedinthe upper end of the piston 84 When the engine is suddenly accelerated, the valve 67 will tend to leap upwardwith a certain amount of sud denness. Normally, this would tend toproduce a momentary unduly lean mixture. \Vhile a toosudd'en upwardmovement of the valve is retarded by the piston 84- and the plate 85, the richness required for this quick acceleration is attained by me as follows: As the valve moves upward quickly, a small amount of fuel is forced from thechamber 96, through the passageway 94 and into the member 62. This temporarily increased richness isextremelyadvantageous, inasmuch as it will be noted that this increase in richness occurs at exactly that period of running when it is most needed, namely, during rapid or instantaneous acceleration. It will also be noted that this temporary raising of additional rich liquid fuel will becbut'momentary. To overcome any tendency offorcing-too rich a primary fuel through the passageway 94' upon sudden acceleration,I show a passage 97 formed longitudinally of the valve 67 and concentric with, and'exteriorly oft'he passage 94. This passage,at its'upp'er'end, connects withthe air supply through the chamber 7 6. At its'lower end, it connects with the transverse passage95. The primary fuel supplied through the passage 94 isthus' mixed with Correspondingly, when the enginethrottle is suddenly closed, the retarding effect of the piston '84 will prevent choking of the engine by a possiblesudden increase in richness due to the shuttingoff of the air supply.

Inasmuch as it is important to prevent a sudden rise of the valve whenthe throttle suddenly thrown wide open,than would be to prevent a' sudden fall, I havezprovided the aforementioned'lost motion effect between the two part pistonSt and'85.

It will be obvious thatin its'passage to the point .of consumption, the mixture may be preheated as. by the exhaust of the engine,

thereby preheating the mixture and producing advantages which will be obvious. It

will be un'derstoodthat numerous other'an. rangements and constructions of" parts may be made to fulfill equivalent purposes, and I do not mean to. limit myself to the particular skilled in the art without departing from the.

in the appended claims.' It is therefore intended that these details be interpreted as merely illustrative, andnot in: a limiting sense.

- the fuel mixture is produced.

The manner in which the fuel is fed by suction from the rear tank to the pipe 17 is such as to give the result of the suction always acting upon a constant liquid level regardless of the height of the fuel in the rear tank.

The production of a satisfactory primary mixture is assisted materially by the manner in which the fuel feed from the pipe 17 v is directed so as to change the direction of the fuel feed from the pipe. 17 and its co-action with the air column through 25 with the consequent beneficial results in atomization, and this is still further assisted by the provision of a construction 16 at the terminal end of the pipe 17. a

By the arrangement herein disclosed, I find that I attain a primary mixture in which the air and fuel are mixed together so as to provide a mixture which not only is itself stable, but the stability of which is still further increased in its travel to the point of consump tion.

One of the important features of, my invention is an arrangement whereby a fuel mixture of maximum efiiciency is at all times supplied for combustion purposes, and the proportion of fuel and air contained therein is maintained substantially constant regardless of running conditions, the proportion being such as to give the aforementioned maximum efliciency.

Another important feature of my invention is the employment of a gravity valve such as that shown at 67 as the main controlling factor of the character of mixture to be produced because, not only does it control, as already stated, the air which is the large factor of the mixture, but a gravity valve presents a constant load regardless of suction conditions, and therefore moves exactly in accordance with and proportional to the variation in such suction conditions.

The shape of the valve 6? which is herein illustrated as top-like in character, pos sesses features of advantage in so controlling and directing the flow of air as to cause it to serve its purposes with great efficiency in connection with the directing of the flow of air so that a maximum mixing effect with It will also be observed that I herein show this valve 67 as positioned relatively close to the constricted passageway through 61 and relatively close therefore to the point at which the primary fuel mixture is introduced from the neck 61, which also I have found possesses features of advantage. I

In order to catch any liquid gasoline that may form above the valve 67 I have provided a space 110' adjacent the valve seat with vents which open above the throttle 71 by means of the tube 111 so that the gasoline settling in this space 110 works its way up into the pipe 111 and into the chamber.

Upon viewing the lower part wall of the chamber 80, it will be observed that there is a space 115 between the skirt 116 and the outer wall 117. There is thus provided a clearance so as to eliminate any question of actual. fitting and also to prevent warping or distorting of the parts when they are as sembled or disassembled, and to allow for errors in manufacture and also to permit circulation of the liquid from below the piston 84 to above the piston 84, or vice versa under gradual movements of the throttle 67, and for this'purpose the orifice 118 is provided in the skirt 116. It will be further observed that the U- shaped tubular member 36 has its lowermost portion disposed substantially below the upper level of the constricted passage of the primary mixing venturi serving to stabilize the flow of mixture to the secondary'mixing chamber. Furthermore, the material en-' trapped in the U-shaped tube 36 serveslto supply a small amount of fuel for starting purposes in the manner as hereinbefore described. lVith the'pressure within the secondary mixing chamber equivalent to that of its uum will serve to draw a supply of fuel from that entrapped in the inverted U-shaped member 36. V aporization of this amount of fuel may serve to be sufiicient to start the e11 gine and create the vacuum necessary for drawing up the fuel through the line 17 for forming the primarymixture within the portion A. WVhen the engine is cut 06', any accumulation of fuel beyond that which may be retained in the U-shaped member 36 drains off through the conduit 90 and into the chamber 80, serving not only as an overflow for the fuel after the engine is shut off but as a retarding liquid for the piston member 84, as previously described.

Having thus described my invention and illustrated its use, what I claim as new and desire to secure by Letters Patent, is-.

1. In a fuel feeding system for internal combustion engines operable by the engine induction, a throttle valvefor said system, an air valve at all times responsive to variations in suction conditions as may be formed by said throttle valve, a fuel mixing chamber disposed between said throttle valve and said air valve, an annulalrly formed fuel feeding chamber, means for leading fuel from said annular chamber to said mixing chamber comprising an annular slot, aprimmg connection from said annular chamber .to said mixing chamber, means forfeedmg a primary mixture to said annular chamber comprising a fuel lifting ventur connected directly to a low level storage chamber, said venturi being open to the atmosphere and be ing operated by the induction of said engine.

2-. In a fuel feeding system for internal combustion engines operable by. the'engme atmospheric and the conical valve 67 upon seat, cranking of the motor at low vacinduction, a throttle valve for said system, means for-creating a primary mixture and serving to lift fuel from a-low level fuel storage chamber, means for leading the primary mixture so formed to a secondary mixing chamber, said second means comprising an annularly formed fuel feeding chamber, means for leading fuel from said annular chamber "to said mixing chamber comprising anannular slot, a priming connection from said annular chamber to said mixing chamber, a valve responsive to variations in suction conditions of the engine so as to beoperableat alltimes to convert the final'mixture in accordance with varying operating conditionsand means for dampening the moving action of said valve comprising a cylinder adapted to retain a liquid-and a piston connected with said valve, operable in said liquid. s f

, In a =fuel'feeding system for internal combustion engines operable by the engine induction, a throttle valve for said system, meansfor creating a primary mixture and serving to lift fuel from alow level fuel storagechamber, means for'leading the primary mixture'so formed to a secondary mixing chamber, said second means =comprising an annular-1y formed fuel feeding chamber, means for :leading fuel from said annular chamber to said mixing chamber comprising an annular slot, a 'p'rimingconnection from said annular chamber to said mixing chamber, a valve responsive to variations in suction'conditions of the engine-so as time in :accordance with varying operating conditions and means for dampening the moving action of said valve comprising a cylinder adapted-to retain a liquid'anda piston'connec'ted with said valve, operable in said liquid and fuel conducting means through said valve operable by the movement of'said piston for leading a priming mixture'to the fuel mixing chamber.

4. In a fuel feeding system for internal combustion engines operable by the engine induction, a throttle valve :for said system, means forcreating a primary'mixture and serving to lift fuel fror'na low level fuel storage chamber, means for'leadingt-he primary mixture so formed to a-secondary mixing chambensaid second means comprising an annularly formed fuel feeding chamber,

1 means for leading fuel from said-annular chamber to said mixing chamber comprising an annular :slot, *a -priming connection from said annular chamber to said mixing chamber, a'-valve responsive to variations'in suction conditions of the engine so as to -beoperable at r all :times -to convert the final mixture in accordance with varying operating conditions and means for dampening the moving'action-of said valve comprising a a liquid storage cylinder, apiston connected to be operable at-all timestoyconvert'thefinal mixwith said valveiand movable in said cylinder and means for conducting liquid "fuel to said cylinder from said annular chamber 5. In a fuel feeding system for internal combustion engines operable by the engine induction, .a throttle valve for said system, means for creating a primary mixture and serving to lift fuel from a low level fuel storage chamber, means for leading the primary mixture so formed to a secondary mixing chamber, said second means'comprising an annularly formed fuel feeding chamber, means for leading fuel from said annular chamber to said mixing chamber'compr'ising an annular slot, a priming connection from said annular chamber to said mixing .chamber, a valve, responsive tovariations in suction conditions of the engine so as to beoperable at all times to convert the'fina'l mixture in accordance with varying operating conditions and means for dampening 'themoving action of said valve comprising a'liquid storage cylinder, a piston freely movable infsa id cylinder, means for feedi'ngliquid fuel'from said fuel feedingmeans to said cylinder whereby rapid'movement of saidlpiston will serve .to conduct a priming mixture to said fuel mixing chamber. V

In Witness whereof 'Ihave hereunto signed my name. 7 H l 'CAS'PAR HOEBAUE'R." 

